Project Summary/Abstract The primary objective of the Biospecimen and Pathology Core of the Mayo Clinic Breast Cancer SPORE is to provide an effective centralized resource that will accrue clinically derived breast tissue samples and characterize them for standard clinical pathological parameters (e.g., stage, biomarker status, diagnosis) in order to create banks and cohorts for research purposes. Samples collected will include fresh frozen and formalin fixed paraffin embedded cancers, benign breast disease tissues, and ?normal? mammoplasty/risk reduction specimens, as well as whole blood. The Biospecimen and Pathology Core will also perform expert pathological evaluation of research related histopathological parameters (e.g., atypia in benign breast disease and subclassification of TN tumors) and interpretation of immunostains relevant to SPORE projects (e.g., ER?). The Core will support translational studies by selecting appropriate samples for analysis, assisting with application of special technologies to SPORE projects (e.g., image analysis), and assessing antibody optimizations (e.g., phospho-ER?, cystatin 1/2/4, cystatin 5, and phospho-smad2/3). Immunostain quantification evaluation using digitized image analysis will be developed and standardized by the CORE. The Biospecimen and Pathology Core will coordinate with the Mayo Biospecimen Accessioning and Processing Shared Resource to store cryospecimens and to process blood samples to provide genomic DNA and serum aliquots; it will collaborate with the Mayo Pathology Research Shared Resource to provide histology and other tissue-based services, including paraffin and frozen sectioning, immunohistochemistry, tissue microarray construction, and digital imaging. Working closely with existing infrastructure such as these shared resources minimizes redundancy of services and utilizes existing experience and state of the art equipment.